Instrument.



KR ll499085 E. L. RENSTROM.

' ms'mumsm.

APPUCATIO! HLED DEC. 8,1912- RHEWED A. 2.1915.

1,149,085.. I Patented Aug. 3,1915.

. &1.

- a 9 1 Edward J. .Berwfiam.

E. L. RENSTBOM.

msmumsm. A??UCATIOI FILED DEC. 5, l9l2. RENEWED APR. 2- F915.

LMQQSQ Patented Aug. 3, 1915.

2 SHEETS-8BiST Z- given angle is indicaied on the scale 6, the movement of the section 2 being secured by movin the section 4 through the sleeve 20 tows the sleeve 8. The Qrecise adjustmeut is obtained by the use or the adjusting screw of the sleeve 20 as previously de- Now by adding the angular degreee indicated on the scales 6 and-15 between the sections 1 and 2 and 2 and 4 and subtracting the sum from 180 will Vi'vc as a result the angle, while the indicated lcngth'of the section 4 on the reading line of sleeve 20 will give the linear dimension of the third side. The g arotractor scale 6 is used when the included in wn angle is less than 90 while the scale '6 is used when such angle is greater than 90. When two known angles and the included side are given section 2, or rather the sleeve 8 there on is adjusted to indicatexbe' length of the known side. One of -ihe known angles is then arnzngcd on the eccle- 8 by adjustment of the section 4% es previousl? described how ing one of the known aligns indicated on the scale 5 blue sleeves 17 and 18 are clamped to respective beam sections 1 and 3 thereby fixing the angular relation of the sections 1 and 2. Section 4 is then adjusted lon itmdinelly ofeection 1 until cbe scale 15 indicates the other lmown angle, and clamped in place. The sum of the angles between the sections 1 end 2 and between sections 2 and 4 subtracted from 180 will 've the unknown angle while the linear imeusion of sections 1 end 2 will give the unknown sides.-

With three sides given the respective dimensions are adjusted on the sections 1, 2 and 4- end the angular relation of the respective sections determined in an obvious manner. With the use of section 3 the urn l-CGOWZI linear dimension ordimensions of right engle triangles may be readily deter mined in on'obvious manner.

In the use of the instrument mathematical computations ordinarily necessary to determine the unknown dimensions together wicbthe time and labor required in such computation are avoided as the instrument will mechanically find the unknown dimension under all conditions where it is possible to determine such unknown dimensions mathematically from the known dimensions.

The respective beam sect ons 1, 2, 3, 4 may be constructed in any sectional area, of any length, or of any materiel, and no limitation is contemplated in this particular.

if desired die oivoe member 3.5 may have a central trenspareni; section in which appear the usual cenbez'ing cross lines, enabling the soctiona 1 our. 2 with the scale 8 to be used esen ordinary loci-actor,

Ibo inside edge of each oem should :oess exec'tly ibrougiz the center of each joint to which they connected, so as to give e perfect point, of angle, or apex of angle and the zeros of each graduated scale should be put directly above the center of each joint they are attached to. The rigid 90 angle should be put outside or under the main beam so as to give measurement to the most acute or obtuse angles. The perpendicular or center beam should be so made that it can be detached quickly, so that instrument can be folded and be put in a. case specially made for it, which can be carried in the pocket.

What is claimed isz- 1. instrument of the class described comprising two beams pivotally connected w th relative angular movement, a. sleeve. slidably mounted on one of said beams, a. plurality of beams pivotally connected to said sleeve, and sliding connections between the said letter beams and one of the limb mentioned beams. l

9. An instrument of the class described comprising a. main beam, o second beam pivotally connected to the main beam for engular edjustment'andrelction thereto, a sleeve slidebly mounted on the second beam, a third and a fourth beam pivotolly connected to the sleeve, independent sliding connecticns between said third and fourth beams and the mom beam, said sliding connection between the "fourth beam and the main beam maintaining a fixed an uler relation between said beams I 3. An instrument of clie class described comprising a main beam, 3 second beam pivotelly connected to the main beam for angular adjustment and relation thereto, a sleeve slidabl mounted on the second beam, 2. ilzird and u ourth beam pivo'mlly connected tothe sleeve, independent sliding connections be tween said third uudiourihbcems and the main beam, said slidin connection between the fourth been: and be main beam maintaining a. fixed angular relation between said beams, the sliding connections between the fourth beam and main beam being mounted for independent pivotal movement.

4:; An instrumentof clan; described comprising a main beam, a. second beam pivotelly connected to the main for augm ler adjustment and relation thereto, a. sleeve slidably mounted on the second beam, a third and a fourth beam pivotally connected tov the sleeve, independent sliding connections between said third and fourth beams and the main beam, said sliding connection between the fourth beam and the main beam mainteiuing a fixed an i sci d beams, Hie slir. 2 con lions between the fourth been: and m n beam being mounted for independent pivoitul movez'nsut, the protrector scale carried by the main beam to cooperate Willi the second beam,

5; An instrument of lilac c ose described 'comprieim; 3 main beam, 1% second beam gur 1 i E 1 i 1 otally connected to the main beam for angulnr and relation tharoto, a sleeve slid:

6. An instrument of tho elm described wmpriaing a main beam, a second beam pivotnliy ponnected to the mam beam for angu- 131 ad%ustment and relation thereto, a. sleeve siidab y amountedv on the second bosim, a third and a fourth beam pivotally connectedto-the sleeve, independent sliding connectionsbetween said third and fourth beams and the, main beam, said siidi connection between the fourth beam and e main beam maintaining a. fixed angular rolation between said beams, the sliding connections between the fourth beam nndmain beam being mounted for independent oivotal movement, the pm 7 tractor scaie carried by the main beam to cooperate with the second beam, and a pro tractor scale carried by the sleeve or second beam for cooperation with the fourth boa-m,

tions against indogendontsliding movomant. In testimon w ereof I aiiix my signature in presenco 0 two witnesses.

EDWARD L. RENSTROM.

Wisnesses:

Boot-mimm J. Mama, J claim A. Parnmom and means for clamping the sliding connec- 

